Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9b9648b6a33d44c…

MALICIOUS

PDF

76.7 KB Created: 2021-05-28 16:29:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: 9a373e4f60efe6127a0e033a8a9c24a4 SHA-1: b6a888fd0f47132e616df338f734f5097b9695b0 SHA-256: a9b9648b6a33d44c4b16b9d06496d5a56c8609496931b2798d11b2352b965418
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, many pointing to disposable domains, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and embedded links are consistent with techniques used to redirect users to malicious sites for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://seumenha.ru/123?utm_term=ap+calculus+limits+review+worksheet+answers PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4415748/normal_5feee2953dbae.pdfIn PDF document text
    • https://nipizizit.weebly.com/uploads/1/3/0/9/130969905/9413734.pdfIn PDF document text
    • https://kusotabemeradu.weebly.com/uploads/1/3/4/8/134873971/95f720e0d3f4563.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409420/normal_603335badd3ec.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459792/normal_6014772db554d.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4370288/normal_60b0128655595.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444882/normal_603e931ae3aa4.pdfIn PDF document text
    • https://jaxugitiboxon.weebly.com/uploads/1/3/5/3/135346561/1135059.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465548/normal_5fc5b0390713d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491969/normal_605f68e64bb90.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446272/normal_5fcbf57c194ed.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369306/normal_600fe4ef0f18d.pdfIn PDF document text
    • https://rofipufexorijol.weebly.com/uploads/1/3/4/6/134656377/mipikoliw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425723/normal_602a48a0e3f2c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/00e6002b-89b8-426b-9139-106b385d3ebb/86681977589.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/454000a9-b767-4128-80f2-20dd321bb70b/amp_kohler_triplex_9200_review.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/97b1c619-8dc1-4967-a040-5c809aade448/razadofumav.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8f53f240-37c8-4b32-8048-846b9dc1714c/the_boy_in_the_striped_pajamas_book.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/afa8de37-bc35-4a62-9afd-d25c7e040673/download_the_weeknd_starboy_lyrics.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/032d2acb-0ed7-45d5-bffd-f3137a1d9cdf/13136709202.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bf797d54-8d2b-4409-a7a9-e99c9c9d0554/13510385699.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8117bb73-668c-48ab-8a90-5f5116a37a94/geligijuviwirixomurugal.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8056dad8-4243-4d73-9c89-548b19dc5088/41070466812.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2d63aa07-7da7-43b3-84c7-46905f96f36d/how_to_use_lg_smart_drum_washer.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bb3e7a21-fd18-4ff7-9f05-ead45d86a22e/walgreens_cool_mist_humidifier_filter.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2df221ab-6e46-4f88-94fd-7876b6e24f83/mevobegajokoba.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eba5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBA5 5376 bytes
SHA-256: f8ab90485ecbfb00db92edaab60725ffea9b9e0fea1752f07ac0c463f8a9bba1
font_01_sfnt_off0000fdd5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDD5 10904 bytes
SHA-256: 33d1343dfb38aec05c4da74ed64372115061e5d224df2f85d237dacfc80be31b